JPS63196865A - Optical current measuring apparatus - Google Patents
Optical current measuring apparatusInfo
- Publication number
- JPS63196865A JPS63196865A JP62028452A JP2845287A JPS63196865A JP S63196865 A JPS63196865 A JP S63196865A JP 62028452 A JP62028452 A JP 62028452A JP 2845287 A JP2845287 A JP 2845287A JP S63196865 A JPS63196865 A JP S63196865A
- Authority
- JP
- Japan
- Prior art keywords
- current
- optical
- magnetic field
- measured
- magneto
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims description 29
- 230000000694 effects Effects 0.000 claims description 10
- 230000010287 polarization Effects 0.000 abstract description 12
- 239000004020 conductor Substances 0.000 abstract description 6
- 238000001514 detection method Methods 0.000 abstract description 3
- 230000035945 sensitivity Effects 0.000 abstract description 3
- 238000005259 measurement Methods 0.000 abstract description 2
- 239000013307 optical fiber Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
Landscapes
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、磁気光学素子のファラデー効果を応用した光
学式電流測定装置の改良に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of an optical current measuring device that applies the Faraday effect of a magneto-optical element.
（従来技術〕
磁気光学素子のファラデー効果を応用した光学式の電流
測定は、被測定電流に比例した磁界を検出することによ
ってなされる。(Prior Art) Optical current measurement using the Faraday effect of a magneto-optical element is performed by detecting a magnetic field proportional to the current to be measured.
従来の測定方法は、第１図（イ）（ロ）に示すように、
被測定電流路（１）の付近に光学式磁界センサ（２）を
配置する。第２図は光学式磁界センサ（２）の構造を示
している０発光素子（４）からの光波は光ファイバ（３
ａ）によって光コネクタ（６ａ）に取付けられているロ
ッドレンズ（７ａ）に導かれ、平行ビームとなって偏光
子（８］に入射する。偏光子がらの出力光は直線偏光波
となり、磁気光学素子（９）に入射する。磁気光学素子
には、被測定電流Ｉにより発生した磁界Ｈが光波伝搬方
向に加わり、偏波面（直線偏光面）は磁界強度Ｈに比例
して回転する。これは、ファラデー効果と呼ばれる効果
である。検光子０１）は旋光子０ωにより偏光子（８）
と相対的に偏波面が４５＠の角度を有するようになって
いる。検光子（１１ンからの出力光の強度は、ファラデ
ー効果による偏波面の回転により、従って被測定電流に
よって発生した磁界により変化する。この出力光はロッ
ドレンズ（７ｂ）に入射し、光ファイバ（３ｂ）によっ
て受光素子（５）へと導かれ、受光素子にて光・電気変
換された変換量を検出することによって、磁界強度Ｈ１
従って被測定電流Ｉを測定することができる。The conventional measurement method, as shown in Figure 1 (a) and (b),
An optical magnetic field sensor (2) is placed near the current path to be measured (1). Figure 2 shows the structure of the optical magnetic field sensor (2).The light wave from the light emitting element (4) is transmitted through the optical fiber (3).
a) is guided to the rod lens (7a) attached to the optical connector (6a), which becomes a parallel beam and enters the polarizer (8).The output light from the polarizer becomes a linearly polarized wave, which is a magneto-optical beam. The light enters the element (9).The magnetic field H generated by the current to be measured I is applied to the magneto-optical element in the light wave propagation direction, and the plane of polarization (linear polarization plane) rotates in proportion to the magnetic field strength H. This is an effect called the Faraday effect.The analyzer 01) has a polarizer (8) due to the optical rotation
The plane of polarization has an angle of 45@ relative to that of . The intensity of the output light from the analyzer (11) changes due to the rotation of the plane of polarization due to the Faraday effect, and therefore due to the magnetic field generated by the current to be measured. This output light enters the rod lens (7b) and is connected to the optical fiber ( 3b) to the light-receiving element (5), and by detecting the amount of optical-to-electrical conversion in the light-receiving element, the magnetic field strength H1
Therefore, the current to be measured I can be measured.
前記に述べたように、従来技術では、光学式磁界センサ
は、磁気光学素子中の光路が被測定電流と直交するよう
に、被測定電流により発生する磁場とは平行になるよう
に配置されている。このような配置では、光学式磁界セ
ンサは被測定電流に応じて発生する磁界以外の外部磁界
（外乱）に対しても感知し、精度良く被測定電流値を測
定することが困難であるという問題点があった。As mentioned above, in the prior art, optical magnetic field sensors are arranged so that the optical path in the magneto-optical element is perpendicular to the current to be measured and parallel to the magnetic field generated by the current to be measured. There is. With this arrangement, the optical magnetic field sensor senses external magnetic fields (disturbances) other than the magnetic field generated in response to the current to be measured, making it difficult to accurately measure the value of the current to be measured. There was a point.
本発明はこのような点にかんがみてなされたもので、そ
の目的とするところは、外乱磁界の影響を受けることな
く、被測定電流に応じて発生する磁界を正確に、かつ感
度良く検出する光学式電流測定装置を提供することにあ
る。The present invention has been made in view of the above points, and its purpose is to provide an optical system that accurately and sensitively detects the magnetic field generated in accordance with the current to be measured without being affected by disturbance magnetic fields. An object of the present invention is to provide a type current measuring device.
〔問題点を解決するための手段〕
前記問題点を解決するための手段を実施例に対応する第
３図、第４図により説明する。[Means for solving the problems] Means for solving the problems described above will be explained with reference to FIGS. 3 and 4, which correspond to embodiments.
本発明は、被測定電流により発生する磁界の強さを磁気
光学素子の有するファラデー効果を利用して検出するこ
とにより電流を測定する光学式電流測定装置において、
被測定電流が流れる板状導体（２１）をはさむように磁
気光学素子（２９ａ、 ２９ｂ）を配置し、該磁気光学
素子を通過する光波の伝搬方向が磁気光学素子間で逆方
向になるような手段を講じている。The present invention provides an optical current measuring device that measures current by detecting the strength of a magnetic field generated by a current to be measured using the Faraday effect of a magneto-optical element.
The magneto-optical elements (29a, 29b) are arranged so as to sandwich the plate-shaped conductor (21) through which the current to be measured flows, and the propagation directions of light waves passing through the magneto-optical elements are in opposite directions between the magneto-optical elements. We are taking measures.
第４図に示すごとく、発光素子（２４）からの光波は偏
光子（２８）へ入射され、偏光子からの出力である直線
偏光波は第１の磁気光学素子（２９ａ）により被測定電
流に応じた磁界強度に比例した偏波面の回転を受ける。As shown in Fig. 4, the light wave from the light emitting element (24) is incident on the polarizer (28), and the linearly polarized wave output from the polarizer is converted into the current to be measured by the first magneto-optical element (29a). The plane of polarization is rotated in proportion to the magnetic field strength.
その回転角θは、光波伝搬方向の磁界強度をＨ，ｍ気光
学素子中の光路長を２とするとθ＝Ｖｒ−Ｈ−１となる
。ここで、比例係数Ｖｒはベルデ定数と呼ばれるもので
ある。磁気光学素子（２９ａ）を通った光波は全反射ミ
ラー（３０）に入射し、反射光は、板状導体（２１）に
対して第１の磁気光学素子とは反対側に設置された第２
の磁気光学素子（２９ｂ）に入射する。The rotation angle θ is θ=Vr−H−1, assuming that the magnetic field strength in the light wave propagation direction is H and the optical path length in the optical element is 2. Here, the proportionality coefficient Vr is called the Verdet constant. The light wave that has passed through the magneto-optical element (29a) is incident on the total reflection mirror (30), and the reflected light is transmitted to the second magneto-optical element, which is installed on the opposite side of the plate conductor (21) to the first magneto-optical element.
is incident on the magneto-optical element (29b).
第２の磁気光学素子に加わる磁界の方向は、光波伝搬方
向とともに、第１の磁気光学素子の場合と反対方向であ
る。従って、第２の磁気光学素子による偏波面の回転は
、第１の磁気光学素子の場合と同方向、同角度となる。The direction of the magnetic field applied to the second magneto-optical element is opposite to the direction of the first magneto-optical element as well as the light wave propagation direction. Therefore, the rotation of the plane of polarization by the second magneto-optical element is in the same direction and at the same angle as in the case of the first magneto-optical element.
このようにして、本発明によれば、被測定電流による偏
波面の回転角が２倍になるため、それだけ電流の測定悪
魔がよ（なる。In this way, according to the present invention, the angle of rotation of the plane of polarization due to the current to be measured is doubled, which makes measuring the current that much more difficult.
また、本発明のように、板状導体をはさむように第１、
第２の磁気光学素子を配置すると、被測定電流によって
発生する磁界以外の外部磁界（外乱）が発生している場
合、外部磁界に対する光波の伝搬方向が第１と第２の磁
気光学素子において逆方向になるため、外部磁界による
偏波面回転は２つの磁気光学素子において相殺し、外部
磁界の影響をほとんど無視することができるようになる
。Further, as in the present invention, the first,
When the second magneto-optical element is arranged, when an external magnetic field (disturbance) other than the magnetic field generated by the current to be measured is generated, the propagation direction of the light wave with respect to the external magnetic field is reversed between the first and second magneto-optical elements. Therefore, the polarization plane rotation caused by the external magnetic field is canceled out in the two magneto-optical elements, and the influence of the external magnetic field can be almost ignored.
そのためにも、板状導体の厚みはなるべく薄くすること
が望ましい。For this reason, it is desirable to make the thickness of the plate-shaped conductor as thin as possible.
以下本発明の一実施例を説明する。 An embodiment of the present invention will be described below.
第３図において、（２１）は板状導体、（２２）は光学
式磁界センサ、（２３ａ、 ２３ｂ）は光ファイバ、（
２４）は発光素子、（２５）は受光素子、（２６ａ、
２６ｂ）は光コネクタである。第４図は光学式磁界セン
サ（２３）の内部構造を示しており、ロンドレンズ（２
７ａ）により平行ビームとなった光波は偏光子（２８）
に入射し、偏光子からの出力は直線偏光波となり、磁気
光学素子（２９ａ）により、被測定電流により発生した
磁界強度に比例した偏波面の回転をおこない、全反射ミ
ラー（３０）に入射する。全反射ミラーから第２の磁気
光学素子（２９ｂ）への入射光は、第１の磁気光学素子
（２９ａ）中の光波の伝搬方向と逆になっているが、被
測定電流により発生する磁界の方向も逆になっているた
め、結果として、第２の磁気光学素子により、偏波面は
第１の磁気光学素子による場合と同じ方向に同じ角度だ
け回転する。In Fig. 3, (21) is a plate-shaped conductor, (22) is an optical magnetic field sensor, (23a, 23b) is an optical fiber, (
24) is a light emitting element, (25) is a light receiving element, (26a,
26b) is an optical connector. Figure 4 shows the internal structure of the optical magnetic field sensor (23).
The light wave that has become a parallel beam due to 7a) is polarized by a polarizer (28).
The output from the polarizer becomes a linearly polarized light wave, which is rotated by the magneto-optical element (29a) in proportion to the magnetic field strength generated by the current to be measured, and then enters the total reflection mirror (30). . The incident light from the total reflection mirror to the second magneto-optical element (29b) is in the opposite direction to the propagation direction of the light wave in the first magneto-optical element (29a), but due to the magnetic field generated by the current to be measured. Since the direction is also reversed, as a result, the plane of polarization is rotated by the same angle in the same direction by the second magneto-optical element as by the first magneto-optic element.
以上述べたように、本発明は、光学式電流測定装置にお
いて、磁界すなわち電流検出感度が著しく向上するとと
もに、外部磁界（外乱）の影響を軽減して、精度良く電
流を測定することができるという効果を有する。As described above, the present invention significantly improves the magnetic field, that is, current detection sensitivity, in an optical current measuring device, and reduces the influence of external magnetic fields (disturbances), making it possible to measure current with high accuracy. have an effect.
第１図（イ）（ロ）は従来の光学式電流測定装置の異な
る方向より見た説明図、第２図は従来の光学式磁界セン
サの構成図、第３図は本発明の一実施例を示す光学式電
流測定装置の説明図、第４図は第３図の光学式電流測定
装置に用いられる光学式磁界センサの構成図である。
（１）・・・被測定電流路、 （２１）・・・板状導体
、 （２）、（２２） ・・・光学式磁界センサ、 （
３ａ 、 ３ｂ） 、（２３ａ。
２３ｂ）・・・光ファイバ、 （４）、（２４）・・・
発光素子、 （５）、（２５） ・・・受光素子、 （
６ａ 、６ｂ） 、（２６ａ、 ２６ｂ）−光コネクタ
、（７ａ 、 ７ｂ） 、（２７ａ、 ２７ｂ）・＝ロ
ッドレンズ、 （８，２８） −・・偏光子、 （９）
、（２９ａ、 ２９ｂ）−４ｆｆ気光学素子、００・・
・旋光子、 （３０）・・・全反射ミラー、（１１，３
１）・・・検光子、 （１２，３２）・・・ケース。Figures 1 (a) and (b) are explanatory diagrams of a conventional optical current measuring device seen from different directions, Figure 2 is a configuration diagram of a conventional optical magnetic field sensor, and Figure 3 is an embodiment of the present invention. FIG. 4 is a configuration diagram of an optical magnetic field sensor used in the optical current measuring device shown in FIG. 3. (1)... Current path to be measured, (21)... Plate conductor, (2), (22)... Optical magnetic field sensor, (
3a, 3b), (23a. 23b)...optical fiber, (4), (24)...
Light emitting element, (5), (25) ... Light receiving element, (
6a, 6b), (26a, 26b) - optical connector, (7a, 7b), (27a, 27b) = rod lens, (8, 28) -... polarizer, (9)
, (29a, 29b)-4ff air optical element, 00...
・Optical rotator, (30)... Total reflection mirror, (11,3
1)...Analyzer, (12,32)...Case.
Claims (1)
有するファラデー効果を利用して検出することにより電
流を測定する光学式電流測定装置において、被測定電流
が流れる板状導体をはさむように磁気光学素子を配置し
、該磁気光学素子を通過する光波の伝搬方向が磁気光学
素子間で逆方向であることを特徴とする光学式電流測定
装置。In an optical current measuring device that measures current by detecting the strength of the magnetic field generated by the current to be measured using the Faraday effect of a magneto-optical element, a magnetic An optical current measuring device characterized in that optical elements are arranged and the propagation directions of light waves passing through the magneto-optical elements are opposite between the magneto-optical elements.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62028452A JPS63196865A (en) | 1987-02-10 | 1987-02-10 | Optical current measuring apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62028452A JPS63196865A (en) | 1987-02-10 | 1987-02-10 | Optical current measuring apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63196865A true JPS63196865A (en) | 1988-08-15 |
Family
ID=12249057
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62028452A Pending JPS63196865A (en) | 1987-02-10 | 1987-02-10 | Optical current measuring apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63196865A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02287265A (en) * | 1989-04-28 | 1990-11-27 | Ariake Kogyo Kk | Apparatus for detecting welding magnetic field |
| JPH0351770A (en) * | 1989-07-19 | 1991-03-06 | Tokyo Electric Power Co Inc:The | Method and apparatus for measuring current and method for mounting the same apparatus |
| WO2013021462A1 (en) * | 2011-08-09 | 2013-02-14 | トヨタ自動車株式会社 | Conducting body having current detection head fixed thereto, and current detection head used in manufacture of conducting body |
-
1987
- 1987-02-10 JP JP62028452A patent/JPS63196865A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02287265A (en) * | 1989-04-28 | 1990-11-27 | Ariake Kogyo Kk | Apparatus for detecting welding magnetic field |
| JPH0351770A (en) * | 1989-07-19 | 1991-03-06 | Tokyo Electric Power Co Inc:The | Method and apparatus for measuring current and method for mounting the same apparatus |
| WO2013021462A1 (en) * | 2011-08-09 | 2013-02-14 | トヨタ自動車株式会社 | Conducting body having current detection head fixed thereto, and current detection head used in manufacture of conducting body |
| CN103038647A (en) * | 2011-08-09 | 2013-04-10 | 丰田自动车株式会社 | Conducting body having current detection head fixed thereto, and current detection head used in manufacture of conducting body |
| JP5598538B2 (en) * | 2011-08-09 | 2014-10-01 | トヨタ自動車株式会社 | Conductor to which current detection head is fixed, and current detection head used for manufacturing the conductor |
| US8947072B2 (en) | 2011-08-09 | 2015-02-03 | Toyota Jidosha Kabushiki Kaisha | Conductor to which current detection head is fixed, and current detection head used in manufacture of same |
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